An unlabeled probe based real time PCR and modified semi nested PCR as molecular tools for analysis of chloroquine resistant in Plasmodium vivax isolates from Afghanistan
Abstract Background: Chloroquine (CQ) resistance Plasmodium vivax isolates have been reported from many endemic regions in the world. P. vivax has been reported to be about 95% of the whole malaria in Afghanistan and CQ is prescribing in the first-line treatment of vivax malaria. The pvmdr-1 and pvcrt-o (K10 insertion) genes are the possible markers of CQ-resistance P. vivax isolates. There have been no studies done on the prevalence of molecular markers of CQ-resistance P. vivax in Afghanistan. In the present work, we aimed to evaluate the prevalence of mutations in the pvmdr-1 and K10 insertion in the pvcrt-o genes of P. vivax.Methods: P. vivax isolates were collected from Laghman, Baghlan and Khost provinces. For investigation of polymorphisms of desired regions in pvmdr-1 and pvcrt-o genes, sequencing was applied on the PCR products. We developed a new asymmetric qPCR and melting analysis assay based on unlabeled probe for scanning of K10 insertion in pvcrt-o gene.Results: The analysis of sequencing data of the pvmdr-1 gene showed wild type Y976 and K997 and mutant M958 and L1076 in 33 isolates from three provinces and submitted in GenBank (accession number MK419882-MK419914)Of 36 samples that evaluated for K10 insertion in pvcrt-o, 2/18(11%), 0/10(0%) and 0/8(0%) isolates from Laghman, Baghlan and Khost province possessed K10 insertion, respectively, that confirmed by either sequencing and unlabeled probes and submitted in GenBank (accession number MK292011-MK292046).Conclusion: The existence of 2 samples with K10 insertion and 33 samples with pvmdr1 polymorphism indicating on CQ resistance P. vivax populations in Afghanistan. This can lead to spreading of resistant strains in the society. Furthermore, unlabeled probes are simple and inexpensive alternative tools for screening of P. vivax mutations.